Cotton is known to produce a unique group of terpenoids such as gossypol. The accumulated gossypol and related sesquiterpenoids produced by cotton in pigment glands can be as a resistance against pathogens and herbivores. The majority of cotton sesquiterpenoids are derived from a common precursor which is synthesized by (+)- δ -cadinene synthase (CDN) in gossypol biosynthesis. Through the phylogenetic analysis on G. raimondii and eight other sequenced plant genomes, they found that the cotton, and probably Theobroma cacao, were the only sequenced plant species that possess an authentic CDN1 gene family for gossypol biosynthesis.
Furthermore, the transcriptomic comparison between the fiber-bearing G. hirsutum and the non-fibered G. raimondii demonstrated that three synthases are important for cotton fiber development, including sucrose synthase (Sus), 3-ketoacyl-CoA synthase (KCS) and 1-aminocyclopropane-1-carboxylic acid oxidase (ACO). Meanwhile, the MYB and bHLH transcription factors preferentially expressed in fiber may be useful to explain the molecular mechanisms that are in charge of governing fiber initiation and early cell growth.
Zhiwen Wang, Project Manager at BGI, said, "The completed G. raimondii genome provides a good reference for accelerating the genomic research on tetraploid cotton species such as G. hirsutum and G. barbadense. It also will lay a solid foundation for researchers to further boost cotton quality and productivity by comprehensively exploring the genetic mechanisms underlying cotton fiber initiation, gossypol biosynthesis and resistance against pathogens and herbivores."
|Contact: Jia Liu|